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SGSN: Use dummy all-zero MSISDN value in PDP Context Act on GTP 

The GTP protocol specification requires us to include the MSISDN IE in
all non-secondary PDP context activations. However, when no real HLR is
used (e.g. via GSUP), we do not have the MSISDN information available
and so far simply sent a zero-length MSISDN IE in GTP.  The latter is a
violation of the spec.

So to resolve this, we now send a 15-digit all-zero dummy MSISDN IE, as
described in TS 23.003.

Change-Id: I8d0a5d52d6cd2a00b5dda060bd41d45056dfa84d
This commit is contained in:
Harald Welte 2016-11-01 03:32:50 +01:00
parent 424656e527
commit 686f4d6a85
1 changed files with 14 additions and 1 deletions
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15
openbsc/src/gprs/sgsn_libgtp.c
View File

@ -59,6 +59,15 @@
#include <gtp.h>
#include <pdp.h>
/* TS 23.003: The MSISDN shall take the dummy MSISDN value composed of
* 15 digits set to 0 (encoded as an E.164 international number) when
* the MSISDN is not available in messages in which the presence of the
* MSISDN parameter */
static const uint8_t dummy_msisdn[] =
{ 0x91, /* No extension, international, E.164 */
0, 0, 0, 0, 0, 0, 0, /* 14 digits of zeroes */
0xF0 /* 15th digit of zero + padding */ };
const struct value_string gtp_cause_strs[] = {
{ GTPCAUSE_REQ_IMSI, "Request IMSI" },
{ GTPCAUSE_REQ_IMEI, "Request IMEI" },
@ -167,12 +176,16 @@ struct sgsn_pdp_ctx *sgsn_create_pdp_ctx(struct sgsn_ggsn_ctx *ggsn,
/* IMSI, TEID/TEIC, FLLU/FLLC, TID, NSAPI set in pdp_newpdp */
/* Put the MSISDN in case we have it */
if (mmctx->subscr) {
if (mmctx->subscr && mmctx->subscr->sgsn_data->msisdn_len) {
pdp->msisdn.l = mmctx->subscr->sgsn_data->msisdn_len;
if (pdp->msisdn.l > sizeof(pdp->msisdn.v))
pdp->msisdn.l = sizeof(pdp->msisdn.v);
memcpy(pdp->msisdn.v, mmctx->subscr->sgsn_data->msisdn,
pdp->msisdn.l);
} else {
/* use the dummy 15-digits-zero MSISDN value */
pdp->msisdn.l = sizeof(dummy_msisdn);
memcpy(pdp->msisdn.v, dummy_msisdn, pdp->msisdn.l);
}
/* End User Address from GMM requested PDP address */